
TOTOGRAPHS OF COMETS, AND OF THE MILKY 
WAY. By E. E. Barnard. 


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Monthly Notices of R.A.S. , March /S99. 
















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Reprinted from the Monthly Notices of the Royal Astronomical Society, 

Vol. LL\, No. 6 . 

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X 



PHOTOGRAPHS OF COMETS, AND OF THE MILKY 

WAY. 


BY 


E. E. BARNARD. 







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354 


Prof. Barnard , Photographs of Lix. 6, 

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Photographs of Comets , and of the Milky Way. By E. E. Barnard. 

I have, at various times, sent a number of photographs of the 
Milky Way, comets, <fcc., &c., to the Royal Astronomical Society, 
but these were not accompanied by any descriptions of the 
pictures. 

It was my intention to describe in detail each one of these 
pictures to facilitate their study, and to put on record some of 
the more important features shown on the plates ; for various 
reasons I was unable to do this when sending the pictures. I 
take the opportunity now, while sending a number of lantern 
slides from these and other pictures, to partially remedy the 
omission. 

The Royal Astronomical Society has published some repro¬ 
ductions and lantern slides from the star and comet pictures 
previously sent. The present descriptions will also cover some of 
these, and for easy reference I shall indicate such pictures by the 
additional designation, R.A S., No. —, the number being that 
given in the “ List of Reproductions of Celestial Photographs 
published by the Royal Astronomical Society ” (see page 210). 
At best, these descriptions will cover only a few of the total lot of 
pictures sent by me to the R.A.S. at various times. 

A few brief remarks of an historical nature may perhaps be 
important before entering on the descriptions. 

While connected with the Lick Observatory, a series of photo¬ 
graphs was made of all the different portions of the Milky Way 
which were visible from that latitude. This work was begun in 
the spring of 1889. The instrument employed, as is well known, 
was a 6-inch portrait—lens of 31 inches focus, which bore the 
name of Willard, and the date 1859, and for this reason I have 
called it the “Willard lens” in all my work. This lens was 
used in the early days of wet plate photography for portrait work 
in a San Francisco photograph gallery. In the early times it 
was necessary to use a large aperture to lessen the duration of 
exposure in taking portraits ; but after the invention of the 
.quick dry plates, such a large lens became unnecessary, and this 
one was discarded for smaller and more convenient lenses. 

Upon experimenting with this large lens, I found, on account 
of its wide held and great light-grasping power, that it was 
specially suited for the photography of the Milky Way, comets, 
<tc. It was attached to a wooden camera box, and was first 
used by strapping it to the tube of the 6-inch equatorial. 
Latterly it was placed on an ordinary equatorial mounting, which 
did not permit continuous exposures to be carried across the 
meridian. 

Besides the pictures of the Milky Way and nebulse, a number 
of photographs were secured of Swift’s Comet of 1892, Holmes’s 



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Comets and the Milky Way. 


March 1899. 


355 


Comet of 1892, Brooks’s Comet of 1893, and Gale’s Comet of 
1894. 

The photographs of the Milky Way made with the Willard 
lens were the first to show its cloud forms and general structure. 
They opened up the means for a thorough study of the Milky 
Way such as had not before existed. Indeed, it is safe to say 
that little or nothing was known of the structural peculiarities 
of the Milky Way before these photographs were made. Visual 
means, on account of the smallness of the field of view, could 
give only the vaguest and most uncertain ideas of its wonderful 
structure. But the extended views given us by the wide field 
of the rapid portrait lens, place before us the Milky Way in all 
its sublimity. Every rift and chasm is shown ; the cloud forms, 
the great nebulous regions, and the singular alignments of stars, 
are all faithfully portrayed for permanent study. It is through 
the study of these details that we shall ultimately know something 
definite concerning the universe of stars in which our own Sun is 
placed. 

For the study of the phenomena of the tails of comets, the 
portrait lens has shown itself most admirably suited. It has 
added an interest to the physical study of these bodies that did 
not exist previously ; for the most interesting of the phenomena 
shown by comets must always escape the visual observer and 
pass unknown, without the aid of the portrait lens and the 
photographic plate. Unlike the planets, the comets often 
traverse the entire solar system. They are, therefore, our only 
means of exploring the regions between the planetary orbits. 
Instead of ponderous bodies like the planets, they are but 
flimsy creations of enormous dimensions. They are thus likely to 
be easily subject to disturbances in their forms that would 
produce no perceptible effect on their motions. What these 
influences may be we do not know ; probably swarms or streams 
of meteors, which we know do exist in space, or possibly some 
other cosmical matter yet unknown. Such objects might be (and 
possibly have been) revealed to us by their effect upon the form 
of the comet’s tail as it sweeps through space. 


Swift’s Comet of 1892. 


This was the first comet to show to the photographic plate 
the extraordinary changes to which these bodies are subject. 
Indeed, if it had not been for the photographic plate we should 
have known nothing of the extraordinary changes that occurred 
in this comet and several that have since appeared. 

Photographs taken April 4 and 5 showed that very rapid 
changes were taking place in the comet ; these changes seemed to 
culminate in the extraordinury phenomenon of April 7. 

A study of the various photographs of this comet would seem 
to show that the observed phenomena can readily be explained by 

A 2 


356 Prof. Barnard , Photographs of lix. 6, 

disturbances in the nucleus, and by the ejection of the matter 
composing the head in a direction away from the Sun. 


1892 April 6 rl 15 11 3o m —i6 h 35™. (Lantern slide.) 

In this photograph there is no resemblance to the appearance 
of the comet on preceding dates. 

The tail consists of two broad streams, the northern of which 
is very bright, and the southern faint. The two streams merge 
together near the head, and at this point there is a quick bend in 
its southern side. A great deal of detail is shown in the brighter 
component in the form of bright streaks and patches. Fine 
threads or short “ whisker tails ” extend back from the head at 
considerable angles to the main tail. There are some indications 
present also of the remarkable disturbance which followed some 
twenty-four hours later. 



1892 April 7 fl 15 11 45™—i6 h 35™. (Lantern slide.) 

R.A.S., No. 10. 



This picture shows a remarkable development in the tail at 
the back of the head, which might be taken for a secondary 
comet with a system of tails of its own. This singular develop¬ 
ment appears on one of a series of thin strands into which the 
tail has separated. This particular strand is the largest and 
brightest and somewhat curved, and becomes suddenly thinner 
near the head. These phenomena are very beautifully shown on 
the photograph. The large mass or secondary comet was doubt¬ 
less thrown off from the nucleus or head some time during the 
preceding twenty-four hours, and must have had a very consider¬ 
able velocity. ~ 


1892 April 24 d 13 11 50™—i6 h io m . (Lantern slide.) 

This is a generally characteristic view of the comet. The 
tail partially separates into a number of streams, and on the north 
side is very sharply defined by what appears to be a thin black 
rift; if this edge of the tail is continued to the comet, it will 
pass south of the centre of the head, and consequently does not 
appear due to a force at that moment seated in the nucleus. 
The south portion of the inner bright tail is irregular near the 
head, and in this resembles some of the peculiarities of the tail 
of April 6. 


1892 April 26 d 13 11 45™—i6 h 10™. (Lantern sljde.) 

The multiple structure of the tail is well shown. It appears 
to be made up of a number of bright strands which centre in the 
head. 


357 


March 1899. Comets and the Milky Way. 

Holmes's Comet and the Andromeda Nebula. 

1892 November 2i d 8 h 55™—io h io m . (Lantern slide.) 

The apparent motion of the comet was so slow that it was 
possible to obtain a sharp picture of both comet and nebula—a 
circumstance that is not likely to happen again soon. 

The short exposure (75 m ) for this picture shows splendidly 
the rapid action of the portrait lens. Nearly everything that is 
usually shown in long exposure photographs of the nebula is 
brought out very clearly with this comparatively short exposure. 
There is a bright speck in the comet near its preceding edge : 
this, however, was a fixed star, and not the nucleus, as might be 
supposed. 

An earlier picture, November 1 o, shows the comet round and' 
sharply defined like a planetary nebula, with a symmetrical 
nebulous atmosphere surrounding it for some distance. That 
photograph also shows an irregular nebulous appendage about a 
degree to the south-east of the comet and attached to it by a hazy 
connection. This particular photograph (a copy of which is in 
the possession of the R.A.S., No. 17) is very suggestive, taken in 
connection with the collision theory offered by several astrono¬ 
mers to account for the sudden appearance of this body. It was 
suggested that the object was not a comet in the ordinary sense 
of the word, but the result of a collision of two asteroids, for the 
orbit seemed to lie in the asteroid zone. The failure to see the 
comet previous to its sudden apparition near the Andromeda 
Nebula, its uncometary appearance, its peculiar freaks, and final 
utter disappearance from the heavens, connected with the nebu¬ 
lous appendage shown in the photograph of November 10, would 
strongly suggest'that the object was not a comet at all, but more 
probably a result of some celestial accident. I think there is no 
question but this “ comet ” will never be seen again, and doubt¬ 
less before now it has ceased to exist as an individual body. 

I do not wish it to be understood that I endorse the theory 
that the apparition of this object was due to the collision of two 
asteroids. It may have been due to something besides the collision 
of one asteroid with another. We know too little about what 
may really exist in that region besides the individual asteroids 
themselves. Certainly many of the phenomena presented by this 
body were entirely uncometary. In some of the stages of its 
existence, however, its appearance was perfectly cometary. I 
have a photograph of it on December 10, when its diameter was 
about ^ degree. It was a well developed comet then, with a 
nucleus and central brightness and a diffusion of the head away 
from the Sun. This is a beautiful picture, and the stars shine 
through the comet everywhere. A month later, after it had 
become excessively faint and diffused, it suddenly (1893 January 
16) assumed the form of a bright nebulous star, and again under¬ 
went a process of expanding and diffusion, and finally disappeared. 


358 


Prof. Barnard, Photographs of 


lix. 6, 


1893 Brooks's Comet. 

Photographically this was the most remarkable comet that 
has yet appeared. It is scarcely necessary to say that had it not 
been for the photographs obtained of it with the Willard lens, we 
should have known nothing whatever of the extraordinary phe¬ 
nomena which were presented by this body, and which I am 
convinced will some day be seen to have a bearing upon a 
problem outside of that of the comet itself and of the highest 
importance to astronomy. 

I have selected five of the photographs of this comet for 
description,, four of which bear directly upon the subject just 
mentioned. 


1893 October 2o d i6 h 35 m —17 11 io m . (Lantern slide.) 

R.A.S., No. 14. 

This picture shows the tail straight, but gradually widening, 
and diffused more or less to the north. From the northern side 
of the head a short diffused tail stretches out for half a degree 
or more, at an angle of some thirty degrees to the main tail. The 
apparent motion of the comet was in a direction nearly perpen¬ 
dicular to the length of the tail towards the north-east, and this is 
the direction from which the disturbance seemed to come in the 
later pictures. 


1893 October 2i d i6 h 37™—17 1 ' i2 m . (Lantern slide.) 

R.A.S., No. 9. 

There is an utter transformation of the comet in this picture. 
The tail is larger and brighter and very much distorted, as if it 
hid encountered some resistance in its sweep through space. This 
disturbance seems to have disrupted the north-east edge of the 
tail. The small side tail has apparently been swept away, while 
the more distant portion of the main tail is streaming in a very 
irregular manner. The entire picture is highly suggestive of an 
encounter with some sort of resistance. Is it possible the tail passed 
through a stream of meteors such as we know exist in space 1 
Whatever the cause may have been, the appearance of the tail 
utterly excludes the idea of the phenomenon being due to irregular 
emission of the matter from the nucleus —an explanation quite 
satisfactory in the case of Swift’s Comet. 

In passing, this particular photograph seems to explain at 
least one of the ancient descriptions of a comet, viz., “ a torch 
appeared in the heavens.” The comet, as shown in the photo¬ 
graph, is sufficiently suggestive of a torch streaming irregularly 
in the wind. 



March 1899. 


Comets and the Milky Way. 


359 


1893 October 22 d i6 h 30™—17 11 12™. (Lantern slide.) 

No. 13. 



The tail appears a total wreck in this photograph, and is still 
more suggestive of a disaster. It is very badly broken, and on the 
south-west side hangs in irregular cloud-like masses. Near the 
extremity a large gap exists in the tail, as if something had gone 
through it from the north-east, and a large mass is torn off 
beyond this break and seems to be drifting independent of the 
comet.. Several of the other photographs which I obtained of 
this object show similar masses disconnected from the tail. 


1 893 November 2 d i6 h io m —17 11 25 111 . (Lantern slide.) / 

(Plate 5.) 


This is, perhaps, the next most remarkable picture of this 
comet, and shows that it was still in a disturbing region. The 
tail looks as if it were beating against a resisting force, and it 
seems to be encountered—as in all the photographs—on the 
advancing side of the tail. The motion of the comet was per¬ 
pendicular to the tail towards the east, and, as will be seen, this 
is the direction from which the resistance seems to come. At one 
point the tail is nearly discontinuous, and at the end it is turned 
off abruptly nearly at right angles, as if at that point a greater 
current of resistance was encountered. 

One or two other photographs show the tail badly broken 
and drifting in irregular fragments through space. These four 
pictures, however, are sufficiently characteristic of the phenomena 
shown by this comet to strongly suggest the idea that the tail 
must have encountered some form of resistance in its journey 
around the Sun, in this part of the heavens, on or about 
October 21, and at other times subsequent. 


1893 November n d i5 h 58™—17 11 35™. (Lantern slide.) 

(Plate 5.) 

. x 

In this photograph, the tail of the comet is straight. It con¬ 
sists, at some distance from the head, essentially of two branches. 
The western branch is sinuous, as if matter were streaming irregu¬ 
larly back from the head, while the northern is very straight. At 
the end of the tail is a condensation which is nearly separated 
from the main tail. 

A slender thread of light, beginning in the hinder part of the 
tail, stretches nearly to the end of the tail and forms the western 
border of the diffused western part of the tail. Near the head 
of the comet the tail is very slender and there are several small 
whisker tails from the rear of the head. 

There is a small meteor trail crossing the south-western part 
of the plate parallel to the comet’s tail. 


Prof. Barnard, Photographs of 


36° 


LIX. 6, 


1893 November 13 d 15 11 25™—17 11 30™. (Lantern slide.) 

P.A.S., No. 61. 



This photograph perhaps properly belongs to the set of 
meteor pictures. 

In the original negative the tail of the comet is shown in a 
straggling manner for some distance beyond the bright star 
(a Can. Ven.) 

Perhaps the most singular thing about this picture is the 
fact that, though it was made on the morning of November 14, 
when there was a considerable number of bright Leonids, the 
great meteor shown on the plate was not a Leonid, for it was 
coming from the north, approximately towards the Leonid 
radiant. The meteor was seen with the eye as it shot across the 
sky and burst just off the region of the plate, but unfortunately 
the exact time was not recorded. It would not, however, be far 
from the middle time of the exposure. It was very brilliant— 
brighter than Venus at her greatest brilliancy. 


Photographic Discovery of Comet V., 1892. 


1892 October i2 d 6 h 40 111 —n h . (Lantern slide, enlarged.) 


a = i9 h 32 m ; d— + 12 0 50'. 



This comet was the first one to be discovered by the photo¬ 
graphic plate. A photograph north and west of Altair was made, 
in my regular work of photographing the Milky Way. When 
the plate was developed and examined, a short hazy trail was 
found on it in a =ig h 32™, 8+ 12 0 50' (see A.J. 277). It was at 
once seen that the object was a stranger, as I was perfectly familiar 
with that part of the sky. It was too late to look it up that night 
with the telescope, but the next night itwas sought for and found 
to be a very faint comet moving to the south-west. The discovery 
was telegraphically announced and the comet was generally 
observed. The orbit proved to be of short period—about 6^ 
years. 


Gale’s Comet, 1894. 

1894 May 5 d 8 h 45 111 —n h 15™. (Lantern slide.) 



This is a characteristic photograph of the comet, which was 
mainly remarkable for the slenderness of its tail. 

In this picture the tail is thread-like for some distance from 
the head. Further away it broadens out slightly, and separates 
into two or more parts. The northern edge of the tail appears 
to have a double curvature. 

i he phenomena presented by this comet were not very strik¬ 
ing, though the changes in the tail were interesting. Only very 
slight traces of the tail could be seen with the telescope, and 


March 1899. Comets and the Milky Way. 361 

these only quite close to the head, which was large arid round, and 
did not seem to have anything to do with the formation of the 
tail, that is, there was no indication of the customary blending' 
of the head into the tail. 

Photographs of Meteors. 

A nearly stationary meteor, 1894 August 9 d 14 11 17™ 4 s . 

(Lantern slide.) 

This is the time of the meteor’s appearance. It was nearly 
stationary, with a short path about 12' long. The motion was 
from the north-east to the south-west. The original plate shows 
two other fainter meteors. 

A number of other meteors were photographed at different 
times during my work at Mount Hamilton, but this stationary 
meteor and the one shown on the photograph of Brooks’s Comet, 
1S93 November 13, are the most remarkable. 

^^T897 August io d 15 11 19™—i5 h 49™. (Lantern slide.) 

This photograph was obtained with the Clark 3’4-inch doublet, 
which was kindly lent by the family of the late Alvan Clark, and 
which is a miniature of the Bruce 24-inch, and made from the 
same glass as that lens. The full flight of the meteor is shown 
on the plate. Before disappearing it burst, and beyond this 
point it left a faint trail as it died away. This gives the trail 
the appearance of a long shafted lance. Its path extends from 
a = 2 h 59 m , 8— + 32 0 to a=2 h 59 111 , 8 = + 23 0 . 

1897 August io d 15 11 19™—15 11 49 m . (Lantern slide.) 

This is the same meteor. The picture was made with a small 
lantern lens i ’6 in diameter belonging to Professor Hale. 

This photograph not only shows the meteor train, but it also 
shows the Pleiades near the lower east part of the plate. It is a 
very beautiful picture apart from its scientific value. These 
two photographs were made at the Yerkes Observatory. 

These meteor photographs were reproduced and fully described 
in Popular Astronomy , No. 46. 


Photographs of the Milky Way. 



Star Cloud in Sagittarius. 

1892 June 29 d 9 h 25“—13 11 55™. (Lantern slide.) 
a =i8 h io m : t; 0= — 20 0 . 


This plate shows a large star cloud in Sagittarius, remarkable 
for the two black holes in it. Running southwards from the larger 
and more definite of these holes is a semi-vacant region, which 

^ 3 


362 Prof. Barnard , Photographs of lix. 6, 

branches out into two more or less regular semi-vacant lanes, 
which run for nearly a degree and a half from the hole. At the 
junction of these lanes, about 50' from the hole, is a remarkable 
thread-like stream of small bright stars which extends about 20' 
east and west. Curving slightly at its east end this line of stars 
makes a V-shaped connection with two or three other bright 
stars. At the southerly ends of the dark lanes are two delicate, 
thread-like streams of stars ; the southern one of these extends 
in a gentle curve for nearly 1J degree. This is a very striking 
phenomenon. A similar stream runs eastwards from near the 
upper part of the black hole. Indeed, this is a remarkable 
region for star streams, many of which can be picked out on this 
plate. In the northern part of the slide is shown the celebrated 
Omega Nebula, which loses its characteristic appearance on 
account of the greater extent of nebulosity which the photo¬ 
graph shows compared with what the eye sees. The nebulosity 
extends in a very diffused, fan-shaped manner for over half a 
degree to the eastward from the brighter portion. 

About l^- degree south of the black hole is a group of 
nebulous stars. The largest star of this group is surrounded 
with a circular nebulosity some 20' in diameter. Three degrees 
south of the hole is a bright star, with a partial ellipse of small 
stars extending south-eastwards from it. There are many other 
remarkable features about this plate, which will be at once 
apparent to the eye. 

Near 6 Ophiuchi. 

1894 July 6 d 9 h 30 111 —13 11 5 m . (Lantern slide.) 

« = r7 h 15™ ; o= — 25 0 . (Plate 6.) 

This is certainly one of the most remarkable regions of the 
Milky Way. One would hesitate before coming to a conclu¬ 
sion as to what the ground work here is. Whether it is stars 
altogether, or some nebulosity, or something else, which is neither 
stars nor nebulosity (for it does not closely resemble either), it would 
be difficult to decide in one’s mind. Besides the bed work of small 
stars, there seems to be possibly an infusion of nebulous matter 
over a large portion of the sky in this region. To the east and 
south of 6 Ophiuchi is a vast chasm or rift in the sheetings of 
stars. This has a ragged but definite appearance on its western 
edge, but is more diffused to the east. To the west of the star 6 
will be seen an extended mass of diffused matter among the stars, 
which runs southward and partly bridges the western branch of 
the great rift. At the extreme western end of this rift—beyond 
the hazy diffusion—the vacancy has dark spots in it. Similar 
appearances occur at different points in this part of the sky. 
One can scarcely conceive a vacancy with holes in it, unless there 
is nebulous matter covering these apparently vacant places in 
which holes might occur. The appearance is somewhat like what 


t 


March 1899. 


Comets and the Milky Way. 


3 6 3 


is sometimes seen in the umbra of a sunspot, in which yet blacker 
holes appear. North of d are several minute black markings, one 
of which very much resembles the letter S or the figure 5. Two 
almost parallel semi-vacant streaks, running north and south, will 
be seen on each side of 6 . Still farther north of 0 the Milky Way 
presents a broken appearance, with numerous holes and rifts. 
These all show the peculiarity of darker interiors. This is 
specially shown in another photograph I have made with that 
region central. 

This picture is suggestive of a breaking up or segregation of 
the stratum of stars and nebulosity—-I am not sure it is nebu¬ 
losity—in this portion of the Milky Way. 


North oj 6 Ophiuchi. 

1895 J une 2 5 d 9 h 55 m — r 3 h 55 m - (Lantern slide.) 
c< — 17 h 15 111 ; c= — 22 0 . 



This photograph shows still better some of the phenomena of 
the preceding picture. It brings out yet more remarkably the 
extraordinary nature of the holes and rifts in this part of the 
Milky Way. The phenomenon of darker holes in the vacancies is 
strikingly shown, and looking at the picture one cannot repress 
the thought that all this region of the Milky Way must have a 
substratum of nebulous matter mixed in freely with the ground 
work of stars. 


The Region of 58 Ophiuchi. 

1895 June 2 6 d io h io m —14 11 i5 m . (Lantern slide.) 

« = 17 11 35 111 ; c=— 22 0 . (Plate 6.) 

This region joins on to the preceding one. It is quite unique, 
however, and the peculiar appearances shown on this plate are 
not repeated in any other part of the Milky Way. 

The bright star in the middle of the slide is 58 Ophiuchi. 
This star occupies the centre of a most remarkable region of 
small, cloudlike masses, which in arrangement seem to have a 
slight spiral tendency. This region, like that of 0 Ophiuchi, is one 
where some doubt as to the existence of slight nebulosity might 
arise. I do not feel certain, however, that these clouds are 
nebulous, for there is lacking that peculiar soft appearance 
always characteristic of the true nebulosities of the sky. 

The Trifid Nebula andM. 8 are shown at the east edge of the 
plate. The cluster in the north-east quarter is M. 23. 

This plate also shows the trail of an asteroid, which Dr. 
Berberich kindly identified as belonging to Euterpe (27), which 
was discovered in 1853 by Hind. To those interested in this 
planet the trail will be found 1^ degree south of 58 Ophiuchi. 


LIX. 6, 


364 /Vo/. Barnard , Photographs of 

It will be easily found on the large 10x8 glass positive in the 
possession of the Royal Astronomical Society, which is from 
the same negative as the present lantern slide. Indeed, it can 
be picked out on the slide with a magnifier, 0*32 inch almost due 
south of 58 Ophiuchi , in a semi-vacant region, between two of 
the clouds. 


The Nebulous Region of 15 Monocerotis. 

1894 February i d 7 h o m —9 11 25™, clouds then 9 11 50 111 —io h 25™. 

(Lantern slide.) 

a = 6 h 35 m ; <3=4-10°. 

This plate shows w r ell the large diffused nebulosity that 
extends some 3 degrees northwards from the condensed region 
about 15 Monocerotis. The nebulosity spreads over and partly 
veils a portion of the great vacancy which lies north and west of 
15 Monocerotis. To the west of 15 Monocerotis is a curious 
nebula involving several considerable stars. In the upper part 
of this nebula are one or two remarkably small black holes. 
This object, which is extremely faint and diffused visually, was 
discovered with the 12-inch in 1888. The position of this nebula 
is i86o - o 6 h 23 m 27 s +io° f. It involves the two D.M. stars 
+ io°‘it59 and + io 0 , ii 6 o. Close north of this nebula is a 
small nebulous star which w r as also discovered with the 12-inch 
in 1888. Its position is i86cro 6 h 23 111 i4 s -h, +io° 32 /- 6 = 4 = . 
There is also a small vacancy in the nebulosity about this star, 
close south of the star. 

At the south edge of the plate is shown a portion of Swift’s 
nebula 1 ST.G.C. 2237. 

If the plate is carefully examined, many curious lines of 
stars, vacant lanes, &c., will be seen. About 2 degrees south of 
15 Monocerotis is one of tlmse thin lanes or dark lines among 
the stars which, though extremely narrow, runs eastward for 
about 2 degrees. 

Region of M. 11. 

1895 August i6 d 8 h 25™—13b 35 111 . (Lantern slide.) 
a=i8 h 45 m ; c= — 6°. 

9 

This magnificent star cloud is beautifully show r n on this plate 
It was one of the first of the Milky Way clouds photographed in 
1389. 

The small cluster M. 11 lies on the upper or north edge of 
the neck of the large cloud, and looks like a nucleus. The 
western side of the great cloud has several rather sharply marked 
indentations and several detached masses of stars. 

The star 6 Aquilce , on the upper north edge of the great head, 
has two curious sprays of stars extending from it, giving the 


March 1899. Comets and the Milky Way. 365 

appearance of a ram’s horns. The great star cloud ,seems to be 
made up of very small stars, apparently very uniform in size. 
Near the left-hand corner of the plate is shown a beautiful bright 
nebulous star. This is S.D.M. io°*47i3 of the 5*5 magnitude. 
The position for 1855-0 is i8 h 23 111 23-93, S. io° 53-4'. The 
nebulosity about this star is somewhat elliptical. It was dis¬ 
covered on the plates of 1889, and is quite noticeable visually. 
(See Ast. Nach. 31 n, Bd. 130.) The bright star near the N.E. 
edge of the plate is A. Aquilce. The great star cloud seems to 
stretch out to and surround this star. 

Region of M. 8 and the Trifid Nebula. 

1895 June 27 d io h 55 111 —14 11 25 111 . (Lantern slide.) 
a=i8 h o m ; S= — 24 0 . 

This slide is intended to show the appearance of the Milky 
Way in the immediate neighbourhood of these two nebulae. It 
gives an excellent idea of the apparent relation they bear to the 
rest of the Milky Way. They appear to lie just free of the 
western border of a very brilliant portion of the Milky Way, in 
a partially vacant region, between the bright clouds and the 
region of 58 Ophiuchi. South of these objects is one of the most 
beautiful of all the regions of the Milky Way. 

M. 8 and the Trifid Nebula. 

The same as the preceding, on a larger scale. 

(Lantern slide.) 

This is intended to give a closer view of these objects, and to 
show their relation to each other and to a group of nebulous 
stars which lies about i° east of M. 8. The latter is a very 
remarkable group. The stars are not simply involved in nebu¬ 
losity, but each one is a distinct nebulous star. They are 
connected on the photographs by a delicate nebulous strip 
with M. 8. Several of these were originally discovered visually 
with the 12-inch. 

In reference to this picture it is well to note one thing which 
might be misleading when compared with photographs of these 
objects with larger instruments, where the scale is greater. In 
dealing with the fainter and outlying portions of M. 8 the 
portrait lens is eminently suited, but for the details of the 
brighter parts a larger scale becomes necessary. These details 
are too crowded with the small scale, and the light action is so 
great that what are apparently vacant lanes and regions with a 
larger instrument are filled up and obliterated with the long 
exposure, thus producing an apparent difference in the appear¬ 
ance of the nebula with the portrait lens and with a greater 
telescope. For the details the difference is in favour of the 
larger telescope for a truthful representation of the nebula ; or, 


3 66 


Prof. Barnard, Photographs of Lix. 6, 


in other wo^ds, the small bright details of this nebula are not 
suitable subjects for a short-focus portrait lens, especially when 
using such long exposures as are required to bring out the fainter 
portions of the Milky Way. A comparatively short exposure 
would show these details more faithfully. 


Great Star Cloud in Sagittarius. 

1895 August 13 d 8 h o m —n h 8 m . (Lantern slide.) 



a =i7 h 56 m ; 8 — — 28°. (Plate 7.) 

This is a superb picture of the Milky Way. It most 
emphatically shows the great value of the portrait lens for work 
of this kind, where large details, covering a great region, are to 
be dealt with. 

This beautiful region has always had a special charm for me, 
and I have secured a great many photographs of it. It was the 
first region to be photographed in 1889. 

I can hardly believe that any one familiar with the sky can 
look on this picture without admiring the beauty of structure 
and detail shown on it. Outside of its scientific value, it is a 
picture in itself. 

To the west of the centre is a great plume-like spray of stars 
that apparently is connected with a long rope-like nebula and 
streak of stars running nearly north and south for nearly 2 degrees. 
This nebulous rope of stars is a very singular feature. In some 
photographs of the region which I made with the small lantern 
lens it seems to stand out from the other details near it as if it 
were considerably nearer to us and not connected with the star 
plume, as it appears to be in this photograph. 

In the bright region near the centre of the plate is a tiny 
black hole about 2' or 3' in diameter, well defined, and close 
preceding a small bright group of stars. It is so small and well 
defined on the plate as to look like a defect. The position of 
this object is 17 11 56 111 —27 0 51' (see A.N 2588). It is a most 
remarkable object, with a low power on a 5 or 6-inch telescope. 
In examining this hole with the 36-inch, I found that its southern 
edge was made up qf a dense mixture of milky nebulosity and 
small stars. 

In the north part of the plate is shown M. 8 and the Trifid 
Nebula. 


The Great Nebula of p Ophiuchi and the Vacant Regions near 

Antares. 

1895 June 2i d 9 h 1 2 m —13 11 i2 m ; June 22 d 9 h 5™—13 11 35 m . 

(Lantern slide.) 

a =i6 h 2o m ; 8= — 23 0 . 

It is very difficult to attempt a description of this picture. 
In the centre of the plate is the great nebula, in the centre of 
which p Ophiuchi is apparently placed. But this is only the 


36 7 


March 1899. Comets and the Milky Way. 

main condensation of this remarkable nebula. Its influence 
seems to be very far-reaching, as it has secondary condensations 
about at least two other stars, viz. Cordoba D.M. 24 0 ' 12683 and 
24°'i2684 and 22 Scorpii. The one about the Cordoba stars is 
the most striking, and seems to be made up of four curved 
streams, like the whirls of a great spiral. The great condensa¬ 
tion about p Ophiuchi is most highly suggestive, and with a 
larger telescope would, no doubt, prove to be a most extraordinary 
object, as there are a great many remarkable details shown even 
on this small scale. 

The great nebula occupies a vacant region from which vacant 
lanes stretch irregularly for great distances to the east,- One 
remarkable feature about these dark lanes is the peculiarity 
before mentioned, of darker places in the vacant regions ; this is 
strikingly shown in the present photograph. A nebulous prong 
is seen extending northwards for a short distance from the bright 
star, <r Scorpii , which is evidently connected with the great 
nebula. A large portion of the sky here seems to be covered 
with diffuse nebulosity, to which belongs the condensation about 
p Ophiuchi and the other stars. The peculiarity of this region 
has suggested to me the idea that the apparently small stars 
forming the ground work of the Milky Way here, are really very 
small bodies compared with our own Sun. (See Popular 
Astronomy , No. 45, where the subject is discussed in detail.) 

In the upper north-west corner of the picture is the star 
v Scorpii , which is seen to be involved in a singular wing-like 
nebula. East and south of v are the two stars S.D.M. i9°*4358-9 
and 4361, which are involved in dense nebulosity. The star 
4361 is in the position 1855*0 a=i6 h I2 m I s ; S= — i9°46'. 

These objects were none of them known previous to the first 
photographs I secured of this region in 1895 March, with the 
exception that I had known of nebulosity in this region for many 
years through my comet sweeping. 

I am glad to hear that Professor S. I. Bailey expects to take 
this great nebula up with the Bruce 24-inch at Arequipa, at its 
next apparition, as well as several other objects of this kind. The 
results will be exceedingly interesting. 


The Nebula about v Scorpii. 

1895 May 23 d 9 h o m —I2 h 20 m . (Lantern slide.) 
a — i6 h 5 m ; $= — 19 0 . 

v Scorpii is one of Mr. Burnham’s double stars. In photo¬ 
graphing the region of the great nebula of p Ophiuchi in 1895 
March, I made exposures at the same time with the ij-inch lantern 
lens. On the photographs, with this small lens, the star v Scorpii 
was seen to be involved in dense nebulosity. This star fell at the 
edge of the Willard lens plate, but upon examination it was seen 


368 Prof. Barnard , Photographs of Lix. 6, 

that the larger lens had also shown the nebulosity, and this was 
repeated in subsequent pictures. The present plate is from a 
negative made with the Willard lens specially to show the nebula. 
It is seen to be a wing-like nebulosity, extending north, west, 
and south-east, with the bright star occupying, apparently, the 
centre of brightness. The nebula extends eastwards for some 
distance, where it seems to dull the sky, or where there are 
very few stars. It is well defined and brightest at its western 
edge. The photographs indicate that this nebula is probably 
connected with the great nebula of fj Ophiuchi. 

Region of j 3 Cygni. 

1893 October i2 d 6 h 52“—n h 35™. (Lantern slide.) 
ct=i9 h 25“; r=+26°. 

This picture shows the cloud forms in the Milky Way, south 
and east of (3 Cygni. 

Some 5 0 east of j 3 the dense clustering of small stars rather 
abruptly terminates in great cloud masses. Beyond this the 
Milky Way is very thin, and permits the darkness of space to 
be seen between the stars. One is specially struck with the 
apparent extreme smallness of the general mass of stars in this 
region. 

Region near y Cygni. 

1892 October 20 d 6 h 47™—n h 47™. (Lantern slide.) 
a=i9 h 40 ra ; 8=4-33°. 

This region lies south of y Cygni , which is seen in the north¬ 
east half of the photograph. 

The north-west part of the plate is covered with a more or 
less uniform sheet of small stars, so densely crowded as to 
intercept the view of space beyond, while the south-east portion 
is overspread with a very thin sheeting of stars projected against 
the blackness of space. The contrast between the two conditions 
is very beautiful and striking. The stars here are also remarkably 
uniform in size. 

The original negative shows a great deal of nebulosity about 
y Cygni in the form of brightish strips and patches, which 
slightly give the impression of a spiral arrangement to the 
nebulosity ; these have been sacrificed, however, in the slide 
to show the structure of the Milky Way to the best advantage. 

Nebulous Region near a Cygni. 

1893 October 5 d 8 h o m —i4 h 5 m . (Lantern slide.) 
a=2i h o ra + ; 8=4-42° + . 

The plate shows the singular structure of the Milky AYay at 
this point, and the great nebulosities that affect the sky in this 


March 1899. Comets and the Milky Way. 369 

region. It will be seen that the greatest mass of nebulosity seems 
certainly to be mixed up with the stars, and conforms Vith the out¬ 
line of the star masses at the edge of the greatest semi-vacancy. 
This region was first photographed by Dr. Max Wolf. The 
nebulosities are easily seen with almost any sized visual telescope 
when a low power is employed. I was for many years familiar with 
the nebulosity when seeking for comets, though I did not take it for 
real nebulosity. Indeed, this very nebulosity was discovered by 
William Herschel. In a list of great masses of diffused nebulous 
matter, in Phil. Trans, for 1811, pp. 273-278, he gives for 
number 44 of his list (i8oo‘o « = 20 h 51 111 4 s P.D. 46° 51'), with the 
note : “ Faint Milky Nebulosity scattered over this space ; in some 
places pretty bright.” He gives the size in declination as o° 59', 
and in right ascension 2 0 53', or 2'8 square degrees in area. This is 
undoubtedly the object shown on the photographs. 


Region of N.G.C. 6475. 

1894 June 26' 1 9 h 5 m —i2 h io m . (Lantern slide.) 

«= 1 7 h 45 m i S=- 35 ° q/ * 

This beautiful cluster is partly in a brilliant knot or con¬ 
densation of the Milky Way. 

About 3 0 north-east of the cluster is a small semi-vacant 
comma-shaped hole with a considerable star in its centre. This 
hole is about 12' in diameter. 


The Milky Way in Cepheus. 

1893 October 13 d S h 2o m —15 11 2o ra . (Lantern slide.) 

« = 2i h 35 m ; 8= + 57 0 . 

v u 

Near the centre of this plate is a large and singular nebulosity, 
remarkable for the irregular dark lanes that run into and through 
it. My first knowledge of this nebula was its presence near the 
edge of another plate. The present picture was made specially 
to see what the object was. It was found, as shown, to be 
a fine but very singular-looking nebula. 

To the extreme west of the plate, and north of the centre, are 
two small stars near each other. One of these is strongly 
nebulous. It is one of Mr. Burnham’s double stars (/3 1140), 
while the other star close following it is 3 2790. The larger 
star south of the centre of the plate is y Cephei , while the one at 
the north edge is v Cephei. 


370 


Prof. Barnard, Photographs of Milky Way. lix. 6. 


vj . ; 

Region near the Omega Nebula (Jf. 17). 

"(Sh ^ 

1895 July 25 d 9 h 35 111 —i4 h o m . (Lantern slide.) 

«=i8 h 30 111 j d= — 15°* (Plate 7.) 


This is a very interesting region. The centre of the plate is 
covered by a large mass of stars which converges to a point at a 
vacant region in the north part of the plate. Indeed, nearly all 
the masses of stars in this region seem to tend towards this great 
vacancy, as if its formation had something to do with their 
general arrangement. In this hole shines the beautiful nebulous 
star previously mentioned (S.D.M. io 0, 47i3), which is perhaps 
better shown on this plate than on the others. To the south-west 
of the centre of the plate is the celebrated Omega or Swan 
Nebula (M. 17), and at the lower south-west corner is the fine 
star cloud, with the dark holes jDreviously mentioned. 


All the times given in these descriptions are eight hours slow 
of Greenwich, except the two plates made at the Yerkes Obser¬ 
vatory, which are six hours slow of Greenwich. The positions 
given for all the pictures are only very roughly approximate. 

It is perhaps well to state that in none of my work has any 
retouching been resorted to. Every photograph is free from any 
blemish of that kind, which, however it may be tolerated in a 
portrait of the human face (and it is destructive enough of truth 
there), should never be permitted to vitiate the value of an 
astronomical photograph. A defacing scratch, or a misleading 
defect, should be removed, but on no account should results be 
sought for that cannot be got by a skilful and straight develop¬ 
ment. 

In conclusion, I wish to express my sincere obligations 
to Mr. G. W. Ritchey, of this Observatory, who has kindly and 
skilfully made for me nearly all of the lantern slides here pre¬ 
sented. 

r 

Yerkes Observatory, Williams Bay, Wisconsin : 

1898 November. 



Spottiswoode Jt Co. Printers, New-street Square, London. 



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